Tampa, Florida - Hinh Nguyen is one of 36 people who received a letter from the Pinellas County Supervisor of Elections office questioning their citizenship and eligibility to vote. The letter begins by saying "you may not be a U.S. Citizen."

"He was disappointed when he received this letter," says his son, Hieu. "It's not fair. We lived for more than 20 years here, been citizens for more than 12 years. We work hard, pay our taxes like everybody else... to go through the hassle to respond to a letter like this takes our rights away."

Governor Rick Scott's voter purge program has been put on hold while the state sues the U.S. Department of Homeland Security for refusing Florida access to an immigration database. Meanwhile, the U.S. Department of Justice writes a threatening letter to Florida's Secretary of State, saying Florida's method for weeding out fraudulent voters is "faulty," may "lead to errors that harm and confuse eligible voters" and calls on the state to "cease this unlawful conduct."

"Supervisors of Election across the state are caught in the middle," says Earl Lennard, Hillsborough Supervisor of Election.

Hillsborough sent out sent out 72 letters questioning potential voters' eligibility. Lennard says seven proved their citizenship, one appeared as a voter but said he is not a U.S. citizen, and they have not heard back from the other 64.

Hieu says his father served in the Vietnam War and fought alongside Americans, and he still had to fill out the letter proving his citizenship.

The U.S. Department of Justice says Florida's voter purge program comes too close to the 90 day window before a federal election. Florida has a primary election for federal offices are August 14. The DOJ says a list maintenance this big violates the National Voter Registration Act.